Maxillofacial prosthetics is a subspecialty of prosthodontics, providing the clinical rehabilitation treatment of patients who have lost parts of the face due to cancer, trauma, or birth defects. It is an orphan field, a) offering fundamental rehabilitation and improvement in the quality of life to patients who may have exhausted personal or third party funding, b) treating so few patients that it makes the field unprofitable for manufacturers, and c) provides a dental solution to an essentially medical problem. Silicone rubber materials have been used for facial rehabilitation for more than 4 decades with few improvements. There is a clear need for new, alternative, and more economic materials for extraoral maxillofacial prostheses. Research at Gulf South Research Institute in New Orleans by the Principal Investigator and others in the 1970s and 1980s developed an alternative low-cost thermoplastic material (chlorinated polyethylene, CPE) that met all toxicological (safety) and physical (effectiveness) requirements. A limited clinical trial at the time yielded equivocal results when compared to conventional but costly silicone rubber products. This research will conduct a randomized, single-crossover, double-blinded Phase III clinical trial to evaluate a) experimental thermoplastic CPE, and b) control silicone (Silastic Adhesive A/MDX4-4210) materials for non-inferiority of CPE based on functional & subjective characteristics, and on the quality of life. Both prostheses will be attached with a skin adhesive. In the clinical trial, the patient's missing anatomy will be sculpted and a gypsum mold made. The silicone and the CPE prosthesis will be fabricated and delivered in random order to 50 patients at M.D. Anderson Cancer Center, University of Texas, Houston, 30 patients at Toronto Sunnybrook Regional Cancer Centre, and 20 patients at J.G, Brown Cancer Center, University of Louisville (100 total) to be worn for 4 months each. Detailed questionnaires will be filled out by the anaplastologist/laboratory technician, clinicians, before and after the prostheses are worn, and the patient. Quality-of-life before and after wearing each prosthesis will be tested with the Toronto Outcomes Measure for Craniofacial Prosthetics. These methods were designed to test future materials and techniques. The power analysis that determined that 100 patients would be needed used a non-inferiority approach from data in the previous study. The final analysis of the proposed clinical trial will also test for non-inferiority of CPE (experimental) compared to silicone rubber (control). The outcome will determine if the new material is at least equivalent to conventional silicone in important features. Longevity will be estimated by following patients. Material properties, their cost, and processing characteristics will affect use in underserved areas or developing countries. [unreadable] [unreadable]